(1) Field of the Invention
The instant invention relates to torpedo tube launch systems and more particularly to torpedo tube and slide valve grates for preventing weapon communication wires from falling through flow slots in the outer wall of the torpedo tube.
(2) Description of the Prior Art
Torpedo tube launch systems include an impulse tank which surrounds the breech end of the torpedo tube. The impulse tank is part of an ejection system that is operative for forcing water into the torpedo tube to eject a torpedo therefrom. Water from the impulse tank enters the torpedo tube through a plurality of circumferentially spaced flow slots formed in the wall of the torpedo tube. In this connection, an internal cylindrical slide valve is provided for closing the slots. The slide valve is actuated via a power cylinder which is located externally of the torpedo tube. Force is transmitted to the internal slide valve by diametrically opposed brackets which extend through two of the slots in the torpedo tube wall. Each of the torpedo tube slots is provided with a metal grate which extends across substantially entirely the area of the slot. The prior art metal grates comprise a rigid frame having a plurality of wide ribs extending back and forth between the frame. (See FIGS. 1 and 2). The metal grates are necessary because some torpedo weapons utilize communication wire and/or flexible hose systems to link a fired weapon to the ship for command and control purposes. As the communication wire/hose is payed out, the grates are operative for preventing the wire/hose from falling through the slots into the impulse tank where the wire/hose could foul the ejection system.
A typical ejection system provides six circumferentially spaced slots in the torpedo tube. The brackets for connecting the slide valve with the power cylinder extend through two diametrically opposed slots. In the four slots which are not obstructed by the power cylinder brackets, the metal grates (torpedo tube grates 10) are installed directly within the slot openings 12 (See FIG. 1). However, in the two slots 12 which are obstructed by the power cylinder brackets, the metal grates (slide valve grates 14) must be bolted to the breechward edge of the slide valve 16 within the interior of the torpedo tube. (See FIG. 2). In this manner, the slide valve grates 14 are moved into position over the slots 12 when the slide valve is moved to open the slots 12.
While the existing grates 10 and 14 are generally effective in preventing communication wire/hose from falling through the slots, it has been found that the surface area of the existing grates substantially decreases the flow area of the opening between the impulse tank to the torpedo tube. The surface area of the frames and ribs of the grates 10 and 14 effectively reduce the flow area by approximately 25%. In addition, the decreased flow area creates turbulent flow between the impulse tank and the interior of the torpedo tube, and further area creates unacceptable flow losses during system firing evolution. Still further, the turbulent flow causes unwanted acoustic vibration of the ribs.